You seem to want this to check every 10 seconds to see if there is a new version is this the case? If so why so often? I dont know of any software that checks for an update ever 10 seconds.

Is there a dat file that you can download and check version numbers? That is what we did her at AutoIt so we could include the AutoUpdateIt program. Look around there probably is a better way than checking size.

Study the below code. It only checks every 10 minutes, and should work out for you. You may want to consider getting SciTE it helps with formatting of AutoIt Scripts. It can be found at SciTE4AutoIt3.